Diazo recording

ABSTRACT

A DRY OR WET DIAZO PROCESS GIVING DEEP COLORED TONES USING AS THE COUPLING AGENT A BENZOTHIAZOLIUM COMPOUND CORRESPONDING TO THE FOLLOWING GENERAL FORMULA:   2-CH3,3-R,5-R1,6-R2,7-R3-BENZOTHIAZOLIUM X(-)   WHEREIN: X- STANTS FOR AN ANION, AND MAY BE MISSING WHEN THE ANION IS PRESENT IN THE R GROUP, R STANDS FOR AN ORGANIC GROUP INTRODUCED BY QUATERNIZATION, R1 STANDS FOR HYDROGEN, AND ALKYL GROUP, A PHENYL GROUP, AN ALKOXY GROUP, A HALOGN ATOM, AND AMINO GROUP, CYANO, AN ALKOXYCARBONYL GROUP, AN ACYL GROUP, OR AN ALKYLSULPHONYL GROUP, R2 STANDS FOR HYDROGEN, A C2-C5 ALKYL GROUP, AN ALKOXY GROUP, CYANO, CYANOVINYL OR A HALOGEN ATOM, R3 STANDS FO HYDROGEN, HALOGEN, A SULPHO GROUP OR A SULPHAMYL GROUP, THE BENZENE RING OF THE BENZOTHIAZOLIUM NUCLIUS CARRYING AT LEAST ONE SUBSTITUENT OTHER THAN HYDROGEN AND BEING FREE OF A METHOXY GROUP IN THE 6-POSITION; AND RECORDING MATERIALS USEFUL THEREIN. A PREFERRED BENZOTHIAZOLIUM COMPOUND IS 2,3,5,6-TETRAMETHYL-BENCOTHIAZOLIUM METHYLSULPHATE AND A PREFERRED DIAZONIUM COMPOUND P-DIETHYLANINOBENZENE-DIAZONIUM TETRABOROFLUORIDE.

United States Patent 3,676,140 DIAZO RECORDING Albert Lucien Poot, Kontich, and Henri Depoorter,

Mortsel, Belgium, assignors to Agfa-Gevaert, Mortsel,

Belgium No Drawing. Filed Dec. 2, 1970, Ser. No. 94,575 Claims priority, application Great Britain, Dec. 23, 1969, 62,7 8/69 Int. Cl. G03c 1/58, 5/22, 5/34 US. CI. 96-91 9 Claims ABSTRACT OF THE DISCLOSURE A dry or wet diazo process giving deep colored tones using as the coupling agent a benzothiazolium compound corresponding to the following general formula:

s n CH3 L wherein X- stands for an anion, and may be missing when the anion is present in the R group,

R stands for an organic group introduced by quaternization,

R stands for hydrogen, an alkyl group, a phenyl group, an alkoxy group, a halogen atom, an amino group, cyano, an alkoxycarbonyl group, an acyl group, or an alkylsulphonyl group,

R stands for hydrogen, a C -C alkyl group, an alkoxy group, cyano, cyanovinyl or a halogen atom,

R stands for hydrogen, halogen, a sulpho group or a sulphamyl group, the benzene ring of the benzothiazolium nucleus carrying at least one substituent other than hydrogen and being free of a methoxy group in the 6-position; and recording materials useful therein.

-A preferred benzothiazolium compound is 2,3,5,6-tetramethyl-benzothiazolium methylsulphate and a preferred diazonium compound p-diethylaminobenzene-diazonium tetraborofiuoride.

This invention relates to recording and reproduction of information and to the use of particular chemical compounds in the diazo recording process and material.

As is known the diazo recording process is based on the fact that certain diazo compounds, e.g. diazonium salts, can be decomposed information-wise by light under nitrogen evolution and remaining diazo compound can react with a so-called coupler to form a dye.

In the dry diazo process, also called two-component diazo system, the recording material contains a diazo compound and a coupler. -In addition, it contains an acid that prevents the premature reaction of the diazo compound and the coupler. After the recording material has been exposed to ultraviolet light passing through the original, it is treated with a volatile base such as ammonia. This neutralizes the acid and allows the remaining diazonium compound to combine with the coupler and to form a dye in the image areas.

In the wet or moist diazo process, also called onecomponent diazo system, the recording material contains only the diazo compound. After the recording material has been exposed image-wise to ultra-violet light, it is treated with an alkaline solution containing the coupler. The remaining diazo compound couples with the coupler in the non-exposed areas.

ice

A coupler in the broader definition is a substance that bears an active or mobile hydrogen atom.

Normally used couplers are aromatic hydroxy compounds such as phenols and naphthols of which 2,3'-dihydroxynaphthalene-6-sulphonic acid is a typical example.

Other known couplers contain a reactive methyl or methylene group as described in the Belgian patent specification 459,543 filed Aug. 3, 1945 by Gevaert Photo- Producten NV. and United States patent specification 2,532,744 of James M. Straley, issued Dec. 5, 1950. Typical examples of the latter class are quaternary salts of 2-methyl quinoline, Z-methyl thiazole and Z-methylbenzothiazole, and N-methyl-Z-methylene-benzothiazoline.

The present invention more particularly relates to the use in diazotype recording of couplers that contain an active methyl group.

According to the present invention said couplers are used in the one-component as well as in the two-component diazo system. In the two-component diazotype materials said couplers combine a high coupling activity with a high shelf life of the recording material.

Moreover, as indicated further on many of the couplers according to the following general formula may be used with suitable diazonium compounds to form dyes that have a deep violet to neutral black colour:

1 1120 STOH:

wherein:

X- represents an anion, e.g. a chloride, bromide, iodide, perchlorate, thiocyanate, benzene sulphonate, p-toluene sulphonate, methyl sulphate, ethyl sulphate or a propyl sulphate anion, but X is missing when the anion is already contained in the R group (betaine' salt form), e.g. as a group,

R stands for an organic group introduced by quaternization, e.g. an aliphatic group, including a cycloaliphatic group, a saturated aliphatic group, an unsaturated aliphatic group or one of said groups in substtiuted form, e.g. an alkyl group, more particularly a C -C alkyl group, an allyl group, a cycloalkyl group, e.g. a cyclopentyl or cyclohexyl group, a substituted cycloalkyl group, a substituted alkyl group, e.g. a hydroxy alkyl group, a carboxy alkyl group, a sulpho alkyl group, a sulphato alkyl group, a phospho alkyl group, a phosphoester substituted alkyl group, an acetoxyalkyl group, wherein the substituted alkyl group preferably contains from 1 to 4 carbon atoms, such as in 18- hydroxyethyl, fl-acetoxyethyl, sulphopropyl, sulphobutyl, phosphopropyl, sulphatopropyl, and sulphatobutyl, further the substituted alkyl group wherein M is hydrogen, an onium group or a metal atom; B represents a lower alkylene group such as a methylene, ethylene, propylene, or butylene group, and A represents a methylene group or,

(examples of such substituted alkyl group are described in the United Kingdom patent specification 886,271 filed June 20, 1957 by Gevaert Photo-Producten N.V., e.g. a sulphocarbomethoxymethyl group, an w-sulphocarbopropoxymethyl group, a p(w-sulphocarbobutoxy)benzyl group), and further the substituted alkyl group A -WNH-VB wherein A represents a lower alkylene group such as a methylene, ethylene, propylene or butylene group, B represents an alkyl group, an amino group, a substituted amino group and also a hydrogen atom in the case V is a single bond, and W and V each represent a CO radical, a SO radical or a single bond but at least one of them is a SO- radical (examples of such substituted alkyl groups are described in the United Kingdom patent specification 904,332 filed July 5, 1957 by Gevaert Photo-Producten N.V., e.g. a N-(methylsulphonyl)- carbarnylmethyl group, a v-(acetylsulphamyl)-propyl, or a 5-(actylsulphamyD-butyl group), or an aromatically substituted alkyl group, e.g. a benzyl group, a phenylethyl group, a substituted aralkyl group, e.g. a hydroxy benzyl group, a carboxy benzyl group, a sulpho benzyl group, a halogenated benzyl group, e.g. a bromobenzyl group, and

R stands for hydrogen, an alkyl group including a substituted alkyl group, e.g. a C C alkyl group e.g. methyl, a substituted alkyl group, e.g. benzyl, hydroxy methyl, sulphomethyl or trifluoromethyl, an alkoxy group e.g. methoxy, fluorine, bromine or iodine, amino including substituted amino, cyano, an alkoxycarbonyl group, an acyl group, e.g. an acetyl group, an alkylsulphonyl group, e.g. a methylsulphonyl group,

R stands for hydrogen, a C -C alkyl group, a substituted alkyl group, an alkoxy group, cyano, cyanovinyl, a halogen atom, e.g. fluorine, chlorine or bromine,

R stands for hydrogen, a halogen atom, e.g. fluorine, chlorine or bromine, sulpho or sulphamyl, the benzene ring of the benzothiazolium nucleus carrying at least one of the substituents enumerated for R R and R other than hydrogen and being free from a methoxy group in the 6-position.

2-methyl-benzothiazolium compounds are known as starting materials for the preparation of methine dyes suited for the spectral sensitization of photographic silver halide emulsion materials. For example the preparation of 5-fluoro, S-trifiuoromethyl and S-cyano-Z-methyl-benzothiazoles and their quaternary salts in connection with the manufacture of cyanine dyes has been described by A. I. Kiprianov and L. M. Yagupolsky, Zhur. Obshchei Khim., 22, 2209-15 (1952) or J. Gen. Chem., 22, 2267- 2272 (1952).

The preparation of 6 fluoro-benzothiazolium compounds according to the general formula has been described in J. Gen. Chem., 20, 2111-17 (1950)-C.A. 45, 32674268. The quaternization methods described therein are illustrative for the quaternization of all kinds of benzothiazole bases.

The preparation of 2,5,6 trimethyl-benzothiazolium compounds is described by I. I. Levkoev, N. N. Sveshnikov, N. S. Barvin, M. P. Pashin, J. Gen. Chem., 22, 581 (1952).

The preparation of 2,5-dimethyl-benzothiazolium compounds is described by I. I. Levkoev, N. N. Sveshnikov, E. Z. Kulik, T. V. Krasnova, J. Gen. Chem., 27, 3138 (1957).

The preparation of 5-chloro-2-methyl-benzothiazolium compounds proceeds, e.g., according to W. Konig, Ber., 61, 2065 (1928).

For quaternary salts of Z-methyl-S-methoxycarbonylbenzothiazole reference is made to the United States patent specifications 2,647,051 of William Howelis Vinton and John Charles Firestine, issued July 28, 1953 and 2,647,052 of Alrnore Louis Martin, issued July 28, 1953. The preparation of quaternary salts of 2 methyl 6-methoxy-benzothiazole has been described by Konig, Chem. Ber., 61 (1928) 2065. The preparation of quaternary salts of 2-methyl-5-methoxy-benzothiazole has been described by N. N. Sveshnikov, I. I. Levkoev, Zh. Obshch. Khim., 16, 1071 (1946).

The preparation of quaternary salts of 2,5-dimethyl-6- ethoxybenzothiazole has been described in United States patent specification 3,102,141 of Charles A. Clark and Lester Horwitz, issued Aug. 27, 1963.

The preparation of betaine type salts according to the above general formula may e.g. proceed according to methods described in the United Kingdom patent specifications 886,270 filed June 24, 1957 by Gevaert Photo- Producten N.V., 886,271 filed June 20, 1957 by Gevaert Photo-Producten N.V., and 904,332 filed July 5, 1957 by Gevaert Photo-Producten N.V. and the French patent specification 1,149,769 filed May 14, 1956 by Agfa Wolfen.

Benzothiazolium compounds particularly suited for the use according to the present invention are listed in the following Table 1.

TABLE 1 No. of the Melting coupler R R R R X- point, C u

1 01H; OH; H H 131 2 our, n 0 our, n 168 UH3-- S 0; 1131;333:1211: 81111110111150.01 1. 81 it it lir $32 5 C 11 l, t) (J (,1 ll; 11 11' UI'1J-S 91:11:11: 1511; E 30E, ll F s 0211', Q H u o mso.

9 0111, H H in owns 0, 106

10- C2115 CHZS 0 H H H 270 elm-Q s 02 TABLE I-Continued i fi-CH; R1- [11+ No. of the Melting coupler R R R2 R3 X" Point, C

11 C Ha H H S 3H 12 02H; CFa H H CHgCHg-COOH H H Br C Ha H C H=C H- C N H C H H O C H3 H CzH H H Cl H C Ha H Q CzH; H H S OzNHa 24.0

C Ha- S O;

CH OSO CH O H H 241 1113 3 n a n: F CH3SO4 12s C211 H CN H CzH SO 118 CH H CH=CH-CN H H3304 180 CH: H H I CH3SO4 144 CH F H H CH3SO4 184 CzHa" Cl H C2H SO4 165 CHQCONHCOZCHQ COOCH3 H H B1 (CH2) 4SQ2NH-COCH3 CH H H B1 235 C2H5 0 CH3 H H CH SO 184 CH; H H Bl CHaSO4 162 CH3 H Cl H 0113804 230 C2H5 F H C2H SO4 190 CgHs C O 0 CH3 H H 191 CQHE B1 H H CEH SO] 157 iso-CaH1 CH H H 1 3 (CHz) SO CH: H H "2-2 CH; H H B! 250 CH:

37 (CH2)2-COOH I H H Bl 250 3s H H C H S0 76 -Q *G H CzH5 CN H H C2H SO (CHzhCOOH F H H B1 250 (CH2)2COOH Br H H Br 3 OCH; H H CH SO4 180-200 (CH2)2COOH H F H Br 200 2H CF: H H I 196 C211 Cl H H C2H5SO4 CH H B1 H CHasol 144 (CH2)2C0 OH G H H Bl 180-182 48 (C H2)20H G H H B1 205 (CH2)3CSO3" CH3 H H 115 (CH2) zNHSOz-CH; CH3 H H Bl 0-) CH2CONSOzCH3 CH3 CH3 H 185 CH3 CH3 CH H CH SO4 198 (CHz)4SO2NHCO CH CH3 CH3 H t 222 (CH2)3OSOQ CH CH3 H .i. 83

CH CH3 H Bl 262 CH2- "-C 0 O H (CH2)3OSO H CH3 CH3 250 (CH2)3SO3" CH3 CH3 H ...-......,.M. ...:w, 250 CH3 CH3 CH3 H. 256 C2H5 CH CH H C2H5SO4 130 (CH2)2CO OH CH3 CH H r 260 (CH2) H CH CH H B1 242 CH CH3 OC2H5 H CH SC4 CzHs OH: H C2H5SC4 130 In the photographic reproduction process according to the present invention the benzothiazolium compounds are allowed to couple with diazo compounds. Such diazo compounds are diazonium salts, that optionally may be formed from diazo sulphonates.

The diazonium salts suitable for use according to the present invention can be defined as aromatic compounds bearing a diazo group, of which one valency is satisfied by a carbon atom from the aromatic nucleus and the other valency by an acidic ion.

Particularly suitable diazonium compounds are the stabilized diazonium salts, preferably the zinc chloride double salts and fluoroborates.

Exemplary diazonium salts are those prepared by diazotisation of amines listed in Table 2.

TABLE 2 1) p-Amino-N,N-dimethylaniline (2) p-Amino-N,N-diethylaniline (3 p-Amino-N-ethyl-N-B-hydroxyethylaniline (4) p-Amino-N-ethyl-N-benzylaniline (5) p-Amino-phenylmorpholine (6) p-Amino- (2,5 -diethoxy) -N-benzoylaniline (7) p-Amino- 2,5 -dibutoxy -N-benzy1aniline (8) 4-amino- (2,5-dimethoxy1) -4'-methy1diphenyl sulphide (9) p-Amino-o-ethoxy-N,N-diethylaniline (l) p-Amino-o-chloro-N,N-diethylaniline.

The benzothiazolium compounds containing a S-methyl group or a plurality of methyl groups on the benzene part of the benzothiazolium nucleus, e.g. containing a methyl group in the 6- and 7-position of the benzothiazolium nucleus, and the benzothiazolium compounds containing on the benzene part of the benzothiazolium nucleus at least one methyl group and at least one methoxy group, e.g. containing simultaneously one methyl group in the or 6-position and one methoxy group in the 5- or 6- position of the benzothiazolium nucleus, are particularly suited to produce by coupling with a diazonium compound a dye with neutral black colour.

Diazonium compounds that are preferably used for obtaining a neutral black dye by coupling with the hemethiazolium compounds of the general formula are prepared by diazotisation of primary aromatic amines that in para-position with respect to the primary amino group contain a tertiary amino group such as a dialkylamino group, wherein the alkyl groups may be substituted.

Particularly useful in view of that purpose are the diazonium compounds corresponding to the following structural formulae:

/C2H5 +Nz-N B Fr C9115 (diazo 09) and $2115 +N2NCHzznon (diazo 14) The initial colour obtained with said diazonium compounds and benzothiazolium compounds containing at least one methyl and methoxy group on the benzene nucleus as specified above is violet but turns to neutral black on storage.

Suitable supports or layers used in copying materials according to the present invention have liquid-absorbing characteristics as e.g. ordinary wood pulp paper or rag type paper but also textiles including fabrics made of cotton, cellulose acetate, regenerated cellulose, in other words all types of woven or felted materials, which can be impregnated with a solution containing one or more of the diazonium compounds and/ or couplers, may be used.

For producing transparent diazo prints a transparent sheet is used as support, e.g. a water-impermeable resin sheet. In that connection reference is made to transparent film-supports of use in silver halide photography. When using a water-impermeable resin sheet as support the imaging chemicals are preferably applied into a hydrophilic colloid layer e.g. a gelatin-containing layer.

The radiation sensitive coating composition containing a diazonium compound may contain all kinds of other ingredients, e.g. wetting agents, substances generating a base on heating or a thermally activatable base releasing material, e.g. urea and the substances used for that purpose described, e.g. in the United Kingdom patent specification 983,363 filed May 8, 1961 by Nashua Corporation and the French patent specifications 1,376,708 and 1,376,709 both filed Sept. 17, 1963 by Et. Bauchet Co.,

further optical brightening agents, pigments, e.g. silica and antioxidants improving the whiteness of the areas, in which the diazonium compound has been destroyed. Suitable antioxidants are thiourea, ascorbic acid and allyl isothiocyanate in concentrations ranging from 15 to 25 percent by weight in respect of the diazonium salts.

Preferred amounts of diazonium compound and conpler per sq. m. are in the range of 0.1 g. to 0.5 g. and 0.1 g. to 1.5 g. respectively.

A good storage stability of a coating composition containing a diazonium compound and a coupler according to the general formula can be obtained by using in admixture with said compounds an acid, e.g. citric acid, tartaric acid, boric acid, trichloroacetic acid, tribromoacetic acid, sulphosalicylic acid, phosphoric acid or 1,3,6-naphthalene trisulphonic acid disodium salt in an amount of to 200 percent by weight in respect of the diazonium salt.

Obviously all known principles for preventing premature coupling can be applied in order to obtain a recording material with a storage stability as high as possible. In that connection is mentioned, e.g. the keeping apart of the diazonium compound and the coupler by means of a meltable layer or capsule envelope.

The following example illustrates the present invention.

EXAMPLE A coating composition was prepared by mixing the following ingredients until dissolution of the water-soluble compounds:

p Diethylaminobenzene-diazonium tetraborofluoride (diazo 69) g 6 2,3,5,6-tetramethyl-benzothiazolium methyl sulphate (coupler 52) g 8 Citric acid g 40 Naphthalene-trisulphonic acid trisodium salt g 8 25% aqueous solution of naphthalene-trisulphonic acid disodium salt ml 56 Urea g 20 Colloidal silica g 1 Saponine g 0.5

Water up to 400 ml.

The composition was coated onto a paper base in a proportion of 19 g. per sq. m. and after drying through a line diapositive exposed with ultraviolet light in a common diazotype copying apparatus.

Development proceeded by a treatment with gaseous ammonia.

Initially a violet positive print was formed, whose colour after a few minutes turned into neutral black.

The same results were obtained with the couplers 51 and 53 to 63 and the couplers l-ll, 15 and 19.

The other couplers of Table 1 yielded no neutral black images but images having a deep blue to violet colour.

We claim:

1. A dry or Wet diazo process, which comprises the coupling of a diazo compound with a benzothiazolium compound corresponding to the following general formula:

s up -orn wherein:

X stands for an anion, but X" is missing when the anion is already contained in the R group,

-R stands for an organic group introduced by quaternization,

R stands for hydrogen, an alkyl group, a phenyl group, an alkoxy group, a halogen atom, an amino group, cyano, an alkoxycarbonyl group, an acyl group, or an alkylsulphonyl group,

R stands for hydrogen, a C -C alkyl group, an alkoxy group, cyano, cyanovinyl or a halogen atom,

R stands for hydrogen, halogen, a sulpho group or a sulphamyl group, and wherein the benzene ring of the benzothiazolium nucleus carries at least one of the substituents enumerated for R R and R other than hydrogen and is free from a methoxy group in the 6-position.

2. A dry or wet diazo process according to claim 1, wherein the benzene part of the benzothiazolium compound contains a methoxy group and a methyl group.

3. A dry or wet diazo process according to claim 1, wherein the diazo group is prepared by diazotisation of a primary aromatic amine that in para-position with respect to the primary amino group contains a tertiary amino group.

4. A dry or wet diazo process according to claim 3, wherein the diazonium compound is of the zinc chloride double salt or fluoroborate type.

5. A dry or Wet diazo process according to claim 4, wherein the diazonium compound corresponds to one of the following structural formulae:

CzH

:l BFF 02H,

6. A diazotype recording material containing a diazo compound that is decomposable by irradiation with ultraviolet light and a benzothiazolium compound according to the following formula:

wherein X- stands for an anion, but X" is missing when the I 10 cyano, an alkoxycarbonyl group an acyl group, or an alkylsulphonyl group,

R stands for hydrogen, a C -C alkyl group, an alkoxy group, cyano, cyanovinyl or a halogen atom,

R stands for hydrogen, halogen, a sulpho group or a sulphamyl group, and wherein the benzene ring of the benzothiazolium nucleus carries at least one of the substituents enumerated for R R and R other than hydrogen and is free from a methoxy group in the 6-position.

7. A diazotype recording material according to claim 6, wherein the diazo compound has been prepared by diazotisation of a primary aromatic amine that in paraposition with respect to the primary amino group contains a tertiary amino group.

8. A diazot'ype recording material according to claim 6, wherein the diazo compound is a diazonium salt of the zinc chloride double salt or fiuoborate type.

9. A diazo type recording material according to claim 8, wherein the diazonium salt corresponds to one of the following structural formulae:

CzH

References Cited UNITED STATES PATENTS 3,615,570 10/1971 Werner et al. 9649 X 3,563,752 2/1971 Werner et al. 96-49 X 3,389,996 6/1968 Welch 96-49 3,164,469 1/ 1965 Behmenburg et a1. 96-49 3,415,807 12/1968 Fisher 260-158 3,346,585 10/1967 Dehnert 260158 3,525,733 8/1970 Weaver 260-158 3,245,981 4/1966 Stright 26-l58 NORMAN G. TORCHIN, Primary Examiner I. L. GOODROW, Assistant Examiner US. Cl. X.R. 96- 19, 

